Auto merge of rust-lang#98222 - cjgillot:single-wf, r=michaelwoerister

Only keep a single query for well-formed checking

There are currently 3 queries to perform wf checks on different item-likes.  This complexity is not required.

This PR replaces the query by:
- one query per item;
- one query to invoke it for a whole module.

This allows to remove HIR `ParItemLikeVisitor`.

compiler/rustc_hir/src/intravisit.rs

@@ -65,7 +65,6 @@
 //! example generator inference, and possibly also HIR borrowck.
 
 use crate::hir::*;
-use crate::itemlikevisit::ParItemLikeVisitor;
 use rustc_ast::walk_list;
 use rustc_ast::{Attribute, Label};
 use rustc_span::symbol::{Ident, Symbol};
@@ -76,29 +75,6 @@ pub trait IntoVisitor<'hir> {
     fn into_visitor(&self) -> Self::Visitor;
 }
 
-pub struct ParDeepVisitor<V>(pub V);
-
-impl<'hir, V> ParItemLikeVisitor<'hir> for ParDeepVisitor<V>
-where
-    V: IntoVisitor<'hir>,
-{
-    fn visit_item(&self, item: &'hir Item<'hir>) {
-        self.0.into_visitor().visit_item(item);
-    }
-
-    fn visit_trait_item(&self, trait_item: &'hir TraitItem<'hir>) {
-        self.0.into_visitor().visit_trait_item(trait_item);
-    }
-
-    fn visit_impl_item(&self, impl_item: &'hir ImplItem<'hir>) {
-        self.0.into_visitor().visit_impl_item(impl_item);
-    }
-
-    fn visit_foreign_item(&self, foreign_item: &'hir ForeignItem<'hir>) {
-        self.0.into_visitor().visit_foreign_item(foreign_item);
-    }
-}
-
 #[derive(Copy, Clone, Debug)]
 pub enum FnKind<'a> {
     /// `#[xxx] pub async/const/extern "Abi" fn foo()`

compiler/rustc_hir/src/lib.rs

@@ -27,7 +27,6 @@ pub use rustc_span::def_id;
 mod hir;
 pub mod hir_id;
 pub mod intravisit;
-pub mod itemlikevisit;
 pub mod lang_items;
 pub mod pat_util;
 mod stable_hash_impls;

compiler/rustc_middle/src/hir/map/mod.rs

@@ -612,23 +612,6 @@ impl<'hir> Map<'hir> {
         }
     }
 
-    /// A parallel version of `visit_all_item_likes`.
-    pub fn par_visit_all_item_likes<V>(self, visitor: &V)
-    where
-        V: itemlikevisit::ParItemLikeVisitor<'hir> + Sync + Send,
-    {
-        let krate = self.krate();
-        par_for_each_in(&krate.owners.raw, |owner| match owner.map(OwnerInfo::node) {
-            MaybeOwner::Owner(OwnerNode::Item(item)) => visitor.visit_item(item),
-            MaybeOwner::Owner(OwnerNode::ForeignItem(item)) => visitor.visit_foreign_item(item),
-            MaybeOwner::Owner(OwnerNode::ImplItem(item)) => visitor.visit_impl_item(item),
-            MaybeOwner::Owner(OwnerNode::TraitItem(item)) => visitor.visit_trait_item(item),
-            MaybeOwner::Owner(OwnerNode::Crate(_))
-            | MaybeOwner::NonOwner(_)
-            | MaybeOwner::Phantom => {}
-        })
-    }
-
     /// If you don't care about nesting, you should use the
     /// `tcx.hir_module_items()` query or `module_items()` instead.
     /// Please see notes in `deep_visit_all_item_likes`.
@@ -867,6 +850,10 @@ impl<'hir> Map<'hir> {
         )
     }
 
+    pub fn expect_owner(self, id: LocalDefId) -> OwnerNode<'hir> {
+        self.tcx.hir_owner(id).unwrap_or_else(|| bug!("expected owner for {:?}", id)).node
+    }
+
     pub fn expect_item(self, id: LocalDefId) -> &'hir Item<'hir> {
         match self.tcx.hir_owner(id) {
             Some(Owner { node: OwnerNode::Item(item), .. }) => item,

compiler/rustc_middle/src/hir/mod.rs

@@ -10,6 +10,7 @@ use crate::ty::query::Providers;
 use crate::ty::{DefIdTree, ImplSubject, TyCtxt};
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_data_structures::sync::{par_for_each_in, Send, Sync};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::*;
 use rustc_query_system::ich::StableHashingContext;
@@ -61,6 +62,22 @@ impl ModuleItems {
     pub fn foreign_items(&self) -> impl Iterator<Item = ForeignItemId> + '_ {
         self.foreign_items.iter().copied()
     }
+
+    pub fn par_items(&self, f: impl Fn(ItemId) + Send + Sync) {
+        par_for_each_in(&self.items[..], |&id| f(id))
+    }
+
+    pub fn par_trait_items(&self, f: impl Fn(TraitItemId) + Send + Sync) {
+        par_for_each_in(&self.trait_items[..], |&id| f(id))
+    }
+
+    pub fn par_impl_items(&self, f: impl Fn(ImplItemId) + Send + Sync) {
+        par_for_each_in(&self.impl_items[..], |&id| f(id))
+    }
+
+    pub fn par_foreign_items(&self, f: impl Fn(ForeignItemId) + Send + Sync) {
+        par_for_each_in(&self.foreign_items[..], |&id| f(id))
+    }
 }
 
 impl<'tcx> TyCtxt<'tcx> {

compiler/rustc_middle/src/query/mod.rs

@@ -826,6 +826,10 @@ rustc_queries! {
         desc { |tcx| "checking that impls are well-formed in {}", describe_as_module(key, tcx) }
     }
 
+    query check_mod_type_wf(key: LocalDefId) -> () {
+        desc { |tcx| "checking that types are well-formed in {}", describe_as_module(key, tcx) }
+    }
+
     query collect_mod_item_types(key: LocalDefId) -> () {
         desc { |tcx| "collecting item types in {}", describe_as_module(key, tcx) }
     }
@@ -1399,13 +1403,7 @@ rustc_queries! {
         separate_provide_extern
     }
 
-    query check_item_well_formed(key: LocalDefId) -> () {
-        desc { |tcx| "checking that `{}` is well-formed", tcx.def_path_str(key.to_def_id()) }
-    }
-    query check_trait_item_well_formed(key: LocalDefId) -> () {
-        desc { |tcx| "checking that `{}` is well-formed", tcx.def_path_str(key.to_def_id()) }
-    }
-    query check_impl_item_well_formed(key: LocalDefId) -> () {
+    query check_well_formed(key: LocalDefId) -> () {
         desc { |tcx| "checking that `{}` is well-formed", tcx.def_path_str(key.to_def_id()) }
     }
 

compiler/rustc_typeck/src/check/check.rs

@@ -32,11 +32,6 @@ use rustc_ty_utils::representability::{self, Representability};
 use std::iter;
 use std::ops::ControlFlow;
 
-pub fn check_wf_new(tcx: TyCtxt<'_>) {
-    let visit = wfcheck::CheckTypeWellFormedVisitor::new(tcx);
-    tcx.hir().par_visit_all_item_likes(&visit);
-}
-
 pub(super) fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Abi) {
     match tcx.sess.target.is_abi_supported(abi) {
         Some(true) => (),
@@ -754,7 +749,7 @@ fn check_opaque_meets_bounds<'tcx>(
     });
 }
 
-pub fn check_item_type<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) {
+fn check_item_type<'tcx>(tcx: TyCtxt<'tcx>, id: hir::ItemId) {
     debug!(
         "check_item_type(it.def_id={:?}, it.name={})",
         id.def_id,
@@ -1543,12 +1538,6 @@ pub(super) fn check_mod_item_types(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
     }
 }
 
-pub(super) use wfcheck::check_item_well_formed;
-
-pub(super) use wfcheck::check_trait_item as check_trait_item_well_formed;
-
-pub(super) use wfcheck::check_impl_item as check_impl_item_well_formed;
-
 fn async_opaque_type_cycle_error(tcx: TyCtxt<'_>, span: Span) -> ErrorGuaranteed {
     struct_span_err!(tcx.sess, span, E0733, "recursion in an `async fn` requires boxing")
         .span_label(span, "recursive `async fn`")

compiler/rustc_typeck/src/check/mod.rs

@@ -93,11 +93,7 @@ mod upvar;
 mod wfcheck;
 pub mod writeback;
 
-use check::{
-    check_abi, check_fn, check_impl_item_well_formed, check_item_well_formed, check_mod_item_types,
-    check_trait_item_well_formed,
-};
-pub use check::{check_item_type, check_wf_new};
+use check::{check_abi, check_fn, check_mod_item_types};
 pub use diverges::Diverges;
 pub use expectation::Expectation;
 pub use fn_ctxt::*;
@@ -245,6 +241,7 @@ impl<'tcx> EnclosingBreakables<'tcx> {
 
 pub fn provide(providers: &mut Providers) {
     method::provide(providers);
+    wfcheck::provide(providers);
     *providers = Providers {
         typeck_item_bodies,
         typeck_const_arg,
@@ -253,9 +250,6 @@ pub fn provide(providers: &mut Providers) {
         has_typeck_results,
         adt_destructor,
         used_trait_imports,
-        check_item_well_formed,
-        check_trait_item_well_formed,
-        check_impl_item_well_formed,
         check_mod_item_types,
         region_scope_tree,
         ..*providers